The present invention relates to reinforced drainage blocks and, more particularly, to a mold liner for facilitating the manufacture of such blocks.
The present invention is concerned with the casting of polymer concrete drainage blocks which define a main drainage channel extending from end to end of the block and water inlet passages which extend from openings in the external wall of the block into the main drainage channel.
The present invention relates to curb drainage blocks such as those described in GB-A-2315792 and GB-A-2351109, which are sold by the assignee under the registered trademarks ACO KERBDRAIN and ACO ROADDRAIN. The disclosures of GB-A-2315792 and GB-A-2351109 are incorporated herein by reference.
Where such blocks are required to withstand heavy loading, as in industrial applications and on road carriageways, it is necessary to reinforce the concrete particularly in the area of the thinner sections surrounding the waterway inlets. The technical problem is to locate the reinforcing bars in the correct position during the casting process.
One method of casting such blocks using a hollow plastics liner is described in GB-A-2318081, which is incorporated herein by reference. The present invention is a development of this technique though the liner may be made of materials other than plastic.
In accordance with the present invention there is provided a drainage block liner for use in molding a drainage block, which liner defines at least part of the shape of a main drainage channel of a block to be molded and having sections which define additional openings and passages intended to communicate with the main drainage channel; characterised in that the liner is provided with transverse side bars extending parallel to the main drainage channel on either side of the passages; each bar bearing a plurality of spaced clips for retaining a respective end of a reinforcing bar, which, when mounted in aligned clips will be held in the space between the passages so that when a block is cast the bar will be surrounded by the casting material.
Using a liner that can stay in position in the finished block conveniently allows a required number of drainage bars to be positioned securely during the casting process.
The liner is preferably used with a polymer concrete casting material that will flow around the bars.
The liner may be made of metal, such as cast iron or steel, or plastics such as polypropylene